Transmission system



Jan. 2, 1945.

J. G. MEJEAN ET AL TRANSMIS S ION SYSTEM Filed Sept. 24, 1941 2Sheets-Sheet 1 1.50am 7.3 r

J. G. MEJEAN ET AL TRANSMISSION SYSTEM Filed Sept. 24, 1941 2Sheets-Sheet 2 awa s-s 60$ 77/: xvi-154M Fax/vamp l/E/VF/ INK/V0,

Patented Jan. 2, 1945 UNITED STATES PATENT OFFICE TRANsMIssIoNsYsTnM .1a Jacques Gustave-Mejean,-Westpo! t,and Raymond Henri Amand, Norwalk,Gonm-- The present invention has for its primary object a system bywhich movement can be transmitted from a driving" member to a driven:mem

ber and is characterized by the fact that it is constructed of at leastone mass driven byone of these members, and by at least one cam attachedto the other of these members andagainst which, when .movementistransmitted themass comes in contact with aeer'tain force, thus creating an action which drives the driven member.-

The cam, when there is a. relativemovement between the driven anddriving members, deviates the mass in such a way that areaction iscreated which has a tendency to drivethe'driven-"member, some meansbeing provided: so as toenable,

in this case,'the mass t'o*be' submittedlater on to a deviation inopposite direction without annulling the driving effect.

The invention together with itsolojectives and advantages will be: bestunderstood from a study Applieati n-septemtet 24, 1941, sriai Ne.ingress 14 claims.

(Clu 74 -64) Figure 11 isa schematic.representation showi a ing afurther modification otthis invention.

simplificationasbeingia point A, fixed at the" 15" Figure 12 is aschematic representation showa me further mddification of thisinvention.

Figure 1'3 isv a schematic representation showing a still further'modification of this invention.

Figure 14 is a? perspeetive view of a further modification of theinvention. a a

To describe how the mechanisrn-works, we shall consider the variousefiorts in action in the system. l i

Let us consider (Fig. 15 afroner having a. mass m; which has been shownorrthe drawings, for

end lofarod- AB of which the extremity B'moves along; a 1ine -MM"with aconstant speed V.

Point Aioilows': aiprofile G. D. E; G comprising two-fractions oicircumference GDand EG, both of the following description taken inconnection with the accompanyingdrawingsin which: 1

Figure l is a diagrammaticrepresentation of the theory of the operationofthis invention.

Figure 2 is a force diagram showing the relative efiects ofi theoperating forces F, ;f,. F, f", Of

Figure 1.

Figure 3 is a graphical representation of the displacement of point Bwhen point .A-coincides with point C, plotted against values of F. andI.

Figure 4 is a graphical representation of the variation of the powerderived by plotting the work T against the velocity 0.

Figure his a. diagrammatic representation of A subjected to aconstant/force F1 which is perpendicularto the line wherein the force isbrokendown into its.- component'f orces a Figure 6 is agraphicalrepresentation of the transmitted power curve derived.fromwthei superimpositioir of the power curve 2 taken from Figura andthe power curve q derivedsimilarly from Figure 5.

Figure 7 isav graphical representation of the transmitted power curve"wherein the: curve is:-

shown as" dependent upon: the efiective values of thelcurvesp. q: ofFigurefi; i w

FigureB is a schematic representation showing one embodiment ofthisinvention.

Figure 9 is arschematic representation showing amodification-of thisinven'tion. Figure 10 is a schematic representation showing a furthermodification of this invention;

the theory of operation of this invention except-f that the mass mhasbeen omitted andthe point tang'en-t'to a line-Hu parallel to MM. PartDE of this profile is also parallel to LL. The arc CD has a center 9 andaradius r, and the arc haswcenter O1" ancLa' radius: R; Furthermore,

we shall supposethatMM and'LU are set in a hhrizontal plane-so that itis. not necessary to take into consideration the action of gravity.

When pointA'. moves on the ardCD, that point has at each moment anangular speed waround' the center 0: To this angular speed corresponds acentrifugal-force I i 30* a the profile will cease and willon'ly takeplace again from pointE' to the pointGi Let ussuppose-that oint Ahas-reachedpoint A"; Bis then at B", andpo'intA at that moment has anangular speed 0: around 0' and toflthis angular speed corresponds aforce ,1 such as:

The force isdirected acctrdfng to radius on.

and can be brokend'own into twoforce's f and I' The force ,1" has atendency to drive the profile EG para'liellyto LL' but towards the lefthand side of Fig. 1; f" has a tendency to apply thesprofile 'onitheibas'e'LL Taking. a particular 'case (Fig; 2) we shallshow the relative;ei-fectsfoi me nness and f and er: .sa-rtneircqmpeuenwn' anew;

The. first',..F' has a tendency to drive i .Let us suppose that R=2r andthat the CD=90. The angle GO'E is such that 1:21. cos. a

are

that is to say, cos. u= /2 and 06:60";

The length E? (Fig. 2) is then equal to 2r sin. 04:1.721'.

To obtain the average angular speeds corresponding to" the travels alongthe arcs CD and EG, we can take for unit of tim the travel made by pointB as we have supposed the speed of this point to be constant. SupposingB moves on a parallel line to LL, passing through point 0, and that thelength BA=2r, the angle B is then equal to a. It is then easy to showthat during the travel on arc CD, point A and the rod turn 90 during thetime proportional to 1.722, and that during the'travel on are EG, pointA and the rod turn 60 during the time proportional to 21-. The angularspefids of A along CD and along EG are thereforeproportionalto 125 and30.

If we admit that the angular 'speed of point A is constant duringthetravel on the aforesaid parts, the forces F andfhave for avalue:

'F=m .125 .r =15625.mr j=m.30 .2r- 18000721 At point D and Ep the-values of F and J" are:

' F"='F=15625 m I v .f=f. sin.; 60 =1 550 mr Of what precedes it resultsthat the effort I,

which has a tendency to drive theprofile toward the left can easilybe'about 1 6-Of the effort F which has a tendency to drive this sameprofile toward the right hand sideof the figure; It is possible to tracea diagram representing the variations of F and f in connection with thedisplacements of point B. 1

On Fig. 3 we have plotted the displacements of B, taking for originthe-"point corresponding to a position of B for which A coincides withC,

This is the effort that we shall suppose acts constantly on the profileCD during all the time point A is in contact withthis profile. Point Atravels on profile CD during the length of time t which has for a valueThe space travelled by the speed 1)) during thistirne' will be Duringthe other part ofthe. travel weset Let us call profile on (with a asidethe length DE and as we, neglect the resisting work corresponding to thedisplacement of point A along EG we have 'a displacement of B 2,366,6377 a I U equal to 21 when A goes from E to G. This dis placement takesplace during the time 21' l t V The profile moves during this time adistance 1) I e V 21 Let us design by c a force which acting on theprofile during all the time of the displacement of A along CD and EG,produces a, work equal to the work produced by the force i when Atravels along the arc CD. The displacement of the profile when A hascompletely traveled over it is calculated in the following Way:

The displacement of B, if we suppose the length DE null, has for a valueM2 sin. a-I-l) The corresponding length of time is:

To this length of time corresponds a displacement of the profile But weknow that and the corresponding work is T= K".(l(1?), .v

This expression enables, by givingto Va value a, totrace the curverepresenting the variation of T against 0. a I

Fig; 4 represents this curve. l

Thiscurv cuts the 'abscissa'at its origin. It has a maximum for a valueequal to and has a minimum coincidingwith a double root for a value v=a.

We shall now neglect the mass m of the roller represented by point A(Fig. 5) and we shall suppose pointAis submitted to a constant effort F1constant in intensity and direction and perpendicular to LL. v s

This force F1 canbe broken up in a force F1 according to the normal atpoint A to the profile CD and in another force F"i according to A.B. p

The force F"1 gives on the one hand 'a compositeF'i which tends todisplace the profile towards the right hand side parallelly to LL, andon the other hand a composite F""1, which has a tendency toapply theprofile on the base LL.

An analogous. reasoning can be made when the point A reaches A. onprofile EG. but in this case the component F'z, parallel to LL',is alinsreasons:

assessor:

(IrBecause A is onthe arc EG and that OAf always makeswa big angle withLL;

(2) ca se thoan-gle of theirod: is towards the back compared withthedirectionv of move- 11181117., i x

If we consider a forceiu which will be the average force resulting inthe; integration of the force Fi along the arc CD, we see thatFr andtherefore In are exactly proportional to Fl. If in:

particular V is the speed of B. and if Fr is: pro-r portional to V wehave: i l

r'l xv r'lex'v n -x'w If we admit the setup corresponding to that shownon Fig. 2, A travels along the profile CD during the timeequal. to thaving. the value t 7(2 sin; 05-1).

The: space traveled by the profile has for a value During the otherportion of the travel there is no work done and if we do not takeintoconsideration the portion DE; we have for the displacement of B thevalue 21: The correspond; ingtime is The space traveled by the profileis then If'we chose a force f. which, acting constant- 1y, produces thesame work that in during the travel e, we have If we superpose- (Fig. 6)a. curve of. the third. degree. (1)) represented by. the: equation asderived above, and the parabola (q) repree sentedxby theequation:V1==Jcv also derived above, we; obtain a resulting curve (s);This curve'shows that if wedesi-gn by a. the valueflof the nominal"speedof the driven. member, we obtain between (land i a. rapid. increaseof the transmitted-power butv that between ends. transmitted power stayscomprised. be tween two limits not far apart.

It; is to be. remembered that it. is possible. to change the forms of.the curves p and q; The radius, r of the profile/does not. enter intothe.

cranks land If, diametrically opposed and linked suiting curve adifferent than the one shown on Fig. 6 for speeds between and a.

tem such as the one just described it is possible to move along a line adriven part having a resistance R, and this at different speeds andthough A is linked to a system of which one point, B, has a constantspeed. This system is advantageous because" of the fact that thestarting torque is important. l

The demonstration which has just been made supposes linear displacementsbut could, of course, be made in the case in which B moves in a circle.It then would be necessary to roll the line LL into a circle concentricto the circle previously mentioned.

Figs. 8 to 14 represent schematically and only as-an example, seven waysof performing the operation which is the object of the presentinvention.

In the case of Fig. 8 thesystem comprises two to a driving axis number2. At the extremity of each of these cranks is a connecting rod 3 and3', having rollers 4. and 4' which'will be applied under the effect ofcentrifugal force due to the rotation of the axis 2 against the insideof a.

chamber 5 linked to the driven member and capable of turning around anaxis which is not represented but which is co-axial with the shaft 2.

In what followswe shall only consider the case of the roller 4 aseverything is exactly the same concerning therollef 4'; The shaft 2turns at a constant speed in the direction of the arrow 6; The roller 4being in the position represented, beins. to climb without clashing onthe part 1 of the profile 5 which constitutes a cam which forces thisroller 4 to leave its circular trajectory and calculation of the curve qand therefore this curve y to come nearer to the axis of. rotation. Dueto this deviation, the part 1 of the cam is submitted. to a reactioncorresponding to the case studied in the first paragraph and which has atendency todrive this cam in the direction of the arrow 6. If we supposethat the driving member turns at its nominal speed and that the drivenmember is not rotatin we see that when the roller 4 drives alongthe camI the driven member has a tend-' ency to follow. the driving member witha force depending-upon the curvature of cam 1. When the roller 4 attainsthe summit 8 of the cam, the

driving action due to. the aforesaid reaction is finished and the roller4 deviates in the opposite direction so as to come back to the sameradius i as at the beginning after having traveled on the a after pointIn. this case: there would be no negative influence due to the deviationalong cam 9, but there would be a clashing due to the fact that therollerwould. meet profile 5 with a given speed due to the centrifugal.force. 1 l

Due to the repeated effects of the roller 4 on the cam "I, thedrivenmember builds up speed and there comes a moment when the relative speed.of the roller 4 in connection with thecam has a. tendency to becomenull. At the moment.

when this: synchronizing is obtained, the roller isiimmobile somewhere.along the cam 1 and. they.

due to the centrifugal forcewhich has been studied before in the secondparagraph.

As we have said, this action is independent of the curvature of the camand this is evident because at that moment the roller 4 i immobile onthis cam and is not submitted to any deviation due to this cam. It isclear that the cams l and 9' are identical to the cams and 9 and thatall that has been described concerning the roller 4 is true concerningthe roller 4. i

The symmetrical arrangement according to Fig. 8 is advantageous forsystems wherein balance is essential. It is clear that it would bepossible to multiply the number of rollers and the number of cams. Inthe case of Fig. 8, rod

3 pushes the roller 4. It is, in fact, more advantageous to push theroller than to pull it.

In the case of Fig. 9, the roller 4 is-mounted on a straight arm l whichcan move radially in another arm mounted on a shaft 2. A spring |2whichis not absolutely indispensible drives the roller 4 towards'profile5 even when the shaft 2 doesnt turn. The working conditions of thissystem are about the same as in the case described before. It is clearthat as long as the driven member turns at an inferior speed to that ofthe driving member, the roller 4 is deviated when travelling on the camthi deviation producing a reaction having a tendency to drive the drivenmember and depending on the curve of cam 1. During the negativedeviation along the cam 9, the negative effect is very small andpractically negligible in comparison with the positive eifort exerted onthe cam According to Fig. the mounting is analogous to that of Fig. 9and is'only different by the fact that the roller is diverted from "thetrajectory that it would take if the part following cam I (cam '9)' didnot assist, that is to say, if profile 5 varied suddenly from theminimum radius to the maximum radius. Cam la is submittedbecause ofdeviation from the roller 4 to a reaction having the tendency to drivethe driven member.

In this way roller 4 produces a driving effect not only during itsdeviation along cam l, but

also during its other deviation which insteadof' turning in a planewhich is perpendicular to the axis of rotationof the driving and drivenshafts. Fig. 14 shows another example in which the roller turns aroundan axisparallel to the principal component of the deviation to which thecam that the roller 4 is connected to the shaft 2 by an articulatedlozenge l3. set symmetrically to roller 4. As in the first case thereare two cams l and in order to drive the retarding effect due to thedeviation of roller 4 along cam 9.

Fig. 12 show another example in which roller 4 is linked to a crank bymeans of a connecting rod of variable length comprising apart I5 slidingin a tubular part IS. A spring inside this part I6 continually drivesthe roller 4 as far as possible from the articulation point of the con-In this case roller 4 is necting rod on the crank. The operation of thisdevice is absolutely analogous to that of Fig. 8 but this setup has theadvantage which has been mentioned already in connection withFig. 11,

that is, that the energy built up by the spring when it is giving awayduring the travel of roller 4 on cam l, is restored during the travel oncam 9 and enables the obtainin of a small negative effect.

In the example shown in Fig. 13, the driven member is connected to aprofile 5 as is the case in Fig. 8. This driven member is also connectedto another profile 5a. The-two profiles 5 and 5a constitute a sort ofslide for roller 4. The cam I has the same effect as in the precedingsystems. When roller 4 leaves cam and attains a position shown in fullline .it meets a cam la belonging to the profile 50,, this cam havingsuch a shape submits the roller when there is a relative motion betweenthe driving and driven members.

In fact, the driving shaft l9 isfixed to a plate 20 whichis concentricto a part 2| which has an annular section concentric to the drivingshaft and fixed to a driven member which is not shown. The section ofpart 2| has a part 22 and 22 which are in a perpendicular plane to theshaft H3, and two cams 23 and 23' which have the same object as the camsin the aforesaid examples. A cam 24, 24' follows the cam 23, 23 and hasthe same effect as the cam 9 in the aforesaid examples. A roller 25rolls onparts 22, 23, and 24 when the driving shaft i9 turns in thedirection indicated by arrow 26. The axis of this roller is supported bya part 21 linked to an articulated parallelogram28 to a part 29, fixedon the plate 20. Some means, which are not shown, act vertically on part21 so as to constantly apply the roller with a given force upon thearrow 30 against the section of part 2|. When there is a relativemovement between the driven and driving members, that is to say when thedriven member turns slower thanthe driving member, the roller 25 isdiverted on its trajectory when it begins toclimb on cam 23. Thisdeviation produces a reaction on this cam which has a tendenc to drivepart 2|. Once having traveled on cam 23, the roller travels along cam 24under the effect of the force 30. In this case as inthe above examples,the negative deviation of roller' only because of the action due toforce 30. This force can be obtained by the centrifugal effect of a massturning with shaft I9 and acting on part 21 by means of a lever. Thisforce also can be constant. It could also vary accordin to the relativeposition of the roller with part 2| according to any predetermined law,for instance by means of a cam which would turn at the same time as part2| and which would act onpart' 21 by means of a spring. It wouldtherefore be possible to obtain a force 30 which would be maximum whenthe roller is incontact with cam aromas? thereturn of the roller] in itsfar off position from the axis of "rotation, This profile can,'of

course,be established in such away thatat nominal speed the pressure ofthe roller on this cam 9 may be assmall as it is desirable.

In some cases it maybe advantageousthat cam T b controlledlnrsuch awayas to come'progres sively into position in "order to work againstroller 4. Fig. 11 schematically shows this sort of an arrangement. Inthis case the part comprising the cam l and Skis constituted by the partturning around a parallel axis to the shaft 2 situated at point'3l. attheybeginning of cam I. Means are providedflwhich have not been showminorder to remove completely cam 1 outside the circular profile .32 sothat the roller is not submitted td any deviation during its rotation.These same means enable progressively driving cam 1 into contact withthe roller. Such a disposition enables the starting of the driven shaft2 and the building up of its speed to the nominal speed without theroller 4 encountering any resistance against cam I once the nominalspeed of the driving shaft is obtained. This sort of device isinteresting when this system is to be utilized as a starter, or as aclutch. Of course an arrangement could be made, in the case of Figs. 8,9, and 10 in order that itis not the cam I which would be gradually putinto position of workin with the roller but that it would be the roller5 in; the direction or the movement of: the driving memberwhenthere is arelative movement between said driven and driving members, said camhaving a subsequent portion disposed to cause said mass to take anegative deviation without nullifying the driving effect, saidconnecting rod and saidmass being disposed forwardly with respecttotheangle of rotation, and said first said cam portion havinga greatercurvature than said subsequent portion.

V 2. A'system according to claim 1 characterized by the factthatjtheaforesaid reaction is a functionof the curvatures of said cam.

3. A system according to claim 1 characterized "by'the fact that saidforce assisting thefafores'aidaction isindependent of the curvatures ofwhich would be gradually released in order to work against the cam I.These means would force the roller 4 to stay on a smaller diameter thanthe diameter of Fig. 8 as long as there must be no cooperation betweenthe roller and the cam 1. These means would enable a progressivecooperation by gradually increasing the distance between the roller 4and the axis 2.

What has been said concerning the diagrams shown by Figs. 6 and 7, andabout force 30 shows that the radius of the cam on which the roller 4 or25 acts in order to produce the driving action of the driven member, andthe instantaneous value of the force with which this roller is appliedon the cam, may be chosen in such a way said cam.

. .4. A transmission system balanced statically and dynamically having adriving member-and a driven member alndcomprising, a connecting rodhaving amass secured onlfoneend thereof, the other end being secured toand driven by one of said members and a cam linked to the other memberand against which the movement of this mass is applied with a certainforce, said force exerting an action tending to drive the wardly withrespect to the angle of rotation, and

said first said cam portionhaving a greater curvature thansaidsubsequent portion, said re action being a function of the curvature ofthe cam and said force assisting the aforesaid action being independentof the curvature of the cam.

5. Asystem according to claim 1 characterized by the fact that the saidmass rolls on said cam. 6. A system according to claim 1 characterizedby the fact that the surface of said cam is controlled in such a manneras to permit changes in the contour thereof as it comes into cooperaitshould be necessary to transmit the movement of a driving member havingconstant rotational speed to a driven member which must receive aperiodically variable speed according. to a given law. or vice versa.

We claim:

1. A transmission system balanced statically and dynamically having adriving member and a '05 member comprising a shaft having a crankrigidly secured thereto, saidconnecting rod having one of its endspivotally connected to said crank and said mass being .rotatably securedto the.

other of said ends.

10. A transmission system balanced statically and dynamically having adriving member and a driven member and comprising, a mass driven by oneof said members and a cam linked to the other member and against whichthe movement of this mass is applied with a certain force, said forceexerting an action tending to drive the driven member, continuously, inthe direction of the movement of the driving member, said cam having aportion formed to deviate said mass so ment between the driven anddriving members,

said cam having a subsequent portion disposed to cause the mass to takea negative deviation without. nullifying the driving effect, saiddriving member comprising a shaft having a crank rigidly securedthereto, and a connecting rod, said connecting rod having one of itsends pivotally connected to said crank and said mass being rotatablysecured to the other of said ends, said connecting rod pushing said massagainst said cam when movement is transmitted.

11. 'Asystem according to claim 1 characterized by the fact that itcomprises several masses balanced upon a shaft upon which they rotateand having several cams corresponding to'the number of said masses 12. Asystem according to claim 1 characterized by the fact that it includes asecond cam in the plane of the first said cam, said second camdeviatingsaid mass in a direction'opposite to the motion of thedeviation produced by the first cam, said second cam being so disposedthat said second deviation also produces a reaction tending to drive thedriven member continuously, in the direction of the movement of saiddriving member.

13. A system according to claim 1 characterized byv the fact that itcomprises several'masses connected to andsymmetrically arranged aboutthe driving means. I i

14. A transmission system of the type described comprising" a driveshaft, an annular member concentrically mounted on andrigidly secured tosaid drive shaft, an armmember rigidly secured to said annular memberand extend ing substantially at right angles therefrom, a roller, anarticulated parallelogram linkage means securing said roller to said armmember, a cam, and means whereby said roller is forced into, 00-operative engagement with said cam.

JACQUES GUSTAVE MEJEAN. RAYMOND HENRI AMAND.

